Submission #723840

#	Time	Username	Problem	Language	Result	Execution time	Memory
723840		nicky4321	Cities (BOI16_cities)	C++14	100 / 100	2794 ms	71280 KiB

cities

#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define F first
#define S second
#define PB push_back
#define MP make_pair
#define pii pair<int, int>
#define pll pair<ll, ll>
#define pdd pair<double, double>
#define ALL(x) x.begin(), x.end()
#define vi vector<int>
#define vl vector<ll>
#define SZ(x) (int)x.size()
#define CASE int t;cin>>t;for(int ca=1;ca<=t;ca++)
#define IOS ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
using namespace std;
const int MAX = 1 << 20, MOD = 1e9 + 7;
ll dp[MAX][32];
vector<pll> edge[MAX];

void solve(){
    int n, k, m;
    cin >> n >> k >> m;
    for(int i = 1;i <= n;i++)
        for(int j = 0;j < (1 << k);j++)
            dp[i][j] = 2e18;
    for(int i = 0;i < k;i++){
        int x;
        cin >> x;
        dp[x][1 << i] = 0;
    }
    for(int i = 1;i <= m;i++){
        int u, v, w;
        cin >> u >> v >> w;
        edge[u].PB(MP(v, w));
        edge[v].PB(MP(u, w));
    }
    for(int i = 1;i < (1 << k);i++){
        for(int j = 0;j < k;j++){
            if(i >> j & 1)
                for(int l = 1;l <= n;l++)
                    dp[l][i] = min(dp[l][i], dp[l][1 << j] + dp[l][i ^ (1 << j)]);
        }
        priority_queue<pll> pq;
        for(int j = 1;j <= n;j++)
            pq.push(MP(-dp[j][i], j));
        while(!pq.empty()){
            auto now = pq.top();
            pq.pop();
            now.F = -now.F;
            if(now.F != dp[now.S][i])
                continue;
            for(auto j : edge[now.S]){
                if(now.F + j.S < dp[j.F][i]){
                    dp[j.F][i] = now.F + j.S;
                    pq.push(MP(-dp[j.F][i], j.F));
                }
            }
        }
    }
    ll ans = 2e18;
    for(int i = 1;i <= n;i++)
        ans = min(ans, dp[i][(1 << k) - 1]);
    cout << ans << '\n';
}

int main(){
    IOS
    // CASE
        solve();
    return 0;
}

• Subtask 1: 22 / 22
• Subtask 2: 14 / 14
• Subtask 3: 15 / 15
• Subtask 4: 23 / 23
• Subtask 5: 26 / 26